Engines utilized to power motorcycles include an air inlet for supplying an air charge to the combustion chamber of each cylinder of the engine. Particulate matter in the air, such as dirt and sand, and other air-born matter such as bugs and grass can damage the engine if drawn through the air inlet into the combustion cylinder.
Engines utilized to power motorcycles are susceptible to drawing in dirty air. For example, in automobiles, the air intake is typically positioned well above the ground and shielded in an engine compartment. The engine of a motorcycle is typically not well shielded, and is positioned directly behind the front wheel. The front wheel propels dirt, sand and other matter into the air directly in front of the engine.
Most engines include air cleaners for screening the air before it enters the engine. These air cleaners normally comprise a filter clement positioned within the engine's air intake passage. The filter element is frequently positioned in a passage having an inlet opening facing in the direction of vehicle travel.
Air cleaners utilized in air intakes in this arrangement suffer from several drawbacks. First, the filter element is normally arranged such that the incoming air is directed at a small portion of the air filter element. This small portion of the filter element becomes contaminated more quickly than the remainder of the filter, shortening the longevity of the filter.
Also, the alignment of the air intake for the filter in the direction of the vehicle travel causes engine performance variations. At low speeds air is drawn through the intake by the engine. At higher speeds, movement of the vehicle causes a greater volume of air to pass into the intake, changing the performance characteristics of the engine as compared to the same engine operational parameters when the engine is stationary. At low speeds the air drawn into the air intake is also warmed by the engine. At higher speeds, however, much cooler atmospheric air is drawn into the air cleaner, affecting engine performance by changing the operational parameters of the engine.
A third problem with air cleaners of the type currently utilized is that they do not remove air-borne water. Water in the air charge supplied to the engine generally decreases the engine performance.
An air cleaner which includes an efficient water and solids particulate filtering mechanism and which is arranged with an air intake to prevent air flow variations to the engine is desired.